Suction cup



FIG. 1 is a top perspective view of a suction cup showing my new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a side view thereof;

FIG. 4 is a cross section view thereof taken along line 4-4 of FIG. 3;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof. 

CLAIM The ornamental design for a suction cup, as shown and described. 